/* * Copyright (C) 2012 Bachmann electronic GmbH * Christian Gmeiner * * Backlight driver for ot200 visualisation device from * Bachmann electronic GmbH. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. */ #include #include #include #include #include #include static struct cs5535_mfgpt_timer *pwm_timer; /* this array defines the mapping of brightness in % to pwm frequency */ static const u8 dim_table[101] = {0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 14, 15, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 30, 31, 33, 35, 37, 39, 41, 43, 45, 47, 50, 53, 55, 58, 61, 65, 68, 72, 75, 79, 84, 88, 93, 97, 103, 108, 114, 120, 126, 133, 140, 147, 155, 163}; struct ot200_backlight_data { int current_brightness; }; #define GPIO_DIMM 27 #define SCALE 1 #define CMP1MODE 0x2 /* compare on GE; output high on compare * greater than or equal */ #define PWM_SETUP (SCALE | CMP1MODE << 6 | MFGPT_SETUP_CNTEN) #define MAX_COMP2 163 static int ot200_backlight_update_status(struct backlight_device *bl) { struct ot200_backlight_data *data = bl_get_data(bl); int brightness = bl->props.brightness; if (bl->props.state & BL_CORE_FBBLANK) brightness = 0; /* enable or disable PWM timer */ if (brightness == 0) cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, 0); else if (data->current_brightness == 0) { cs5535_mfgpt_write(pwm_timer, MFGPT_REG_COUNTER, 0); cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN); } /* apply new brightness value */ cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1, MAX_COMP2 - dim_table[brightness]); data->current_brightness = brightness; return 0; } static int ot200_backlight_get_brightness(struct backlight_device *bl) { struct ot200_backlight_data *data = bl_get_data(bl); return data->current_brightness; } static const struct backlight_ops ot200_backlight_ops = { .update_status = ot200_backlight_update_status, .get_brightness = ot200_backlight_get_brightness, }; static int ot200_backlight_probe(struct platform_device *pdev) { struct backlight_device *bl; struct ot200_backlight_data *data; struct backlight_properties props; int retval = 0; /* request gpio */ if (devm_gpio_request(&pdev->dev, GPIO_DIMM, "ot200 backlight dimmer") < 0) { dev_err(&pdev->dev, "failed to request GPIO %d\n", GPIO_DIMM); return -ENODEV; } /* request timer */ pwm_timer = cs5535_mfgpt_alloc_timer(7, MFGPT_DOMAIN_ANY); if (!pwm_timer) { dev_err(&pdev->dev, "MFGPT 7 not available\n"); return -ENODEV; } data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) { retval = -ENOMEM; goto error_devm_kzalloc; } /* setup gpio */ cs5535_gpio_set(GPIO_DIMM, GPIO_OUTPUT_ENABLE); cs5535_gpio_set(GPIO_DIMM, GPIO_OUTPUT_AUX1); /* setup timer */ cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1, 0); cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP2, MAX_COMP2); cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, PWM_SETUP); data->current_brightness = 100; props.max_brightness = 100; props.brightness = 100; props.type = BACKLIGHT_RAW; bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev), &pdev->dev, data, &ot200_backlight_ops, &props); if (IS_ERR(bl)) { dev_err(&pdev->dev, "failed to register backlight\n"); retval = PTR_ERR(bl); goto error_devm_kzalloc; } platform_set_drvdata(pdev, bl); return 0; error_devm_kzalloc: cs5535_mfgpt_free_timer(pwm_timer); return retval; } static int ot200_backlight_remove(struct platform_device *pdev) { /* on module unload set brightness to 100% */ cs5535_mfgpt_write(pwm_timer, MFGPT_REG_COUNTER, 0); cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN); cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1, MAX_COMP2 - dim_table[100]); cs5535_mfgpt_free_timer(pwm_timer); return 0; } static struct platform_driver ot200_backlight_driver = { .driver = { .name = "ot200-backlight", }, .probe = ot200_backlight_probe, .remove = ot200_backlight_remove, }; module_platform_driver(ot200_backlight_driver); MODULE_DESCRIPTION("backlight driver for ot200 visualisation device"); MODULE_AUTHOR("Christian Gmeiner "); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:ot200-backlight"); ='40'>40space:mode:
Diffstat (limited to 'include/dt-bindings/thermal/thermal.h')